Table 2.
Influence of morphology, defects and conductivity on electron transfer properties of electrochemical biosensors based on graphene and graphene composites
| Electrode platform | Morphology | Carbon to Oxygen ratio [%] | ID/IG ratio | Charge transfer resistance (Rct [Ω]) | Surface area [cm2] | Peak-to-peak potential (ΔEp [mV]) | Heterogenous electron transfer rate constant [cm/s] | Capacitance (µF/cm2) | References |
|---|---|---|---|---|---|---|---|---|---|
| Gr-HPHT diamond | Island-like surface structure | N/A | 0.29 | 400 | 0.0183 | N/A | N/A | N/A | [115] |
| Thi-rGO/GCE | Flake-like shape with slight wrinkles | 1.654 | Higher than GO | 33.41 | N/A | N/A | N/A | N/A | [116] |
| Au-rGO-AuPtNP | Bended sheets of graphene | N/A | 1.02 | N/A | N/A | 80 | N/A | N/A | [117] |
| ERGO-GCE | High degree of wrinkles | N/A | 1.80 | Decreases compared to GO | N/A | N/A | N/A | N/A | [118] |
| Anodized epitaxial graphene (EG) | Defects generated on anodized EG surface | Decreased by anodization | Increased by anodization | N/A | N/A | 81 | 0.00981 in [Ru(NH3)6]3+/2+ 0.00101 in [Fe(CN)6]3−/4− | 5.55 at 0.25 V | [58] |
| CRGO/GCE | Curly with 100 nm thickness and 0.8 nm single sheet | 0.117 | 1.38 | 160.8 | 0.092 | N/A | N/A | N/A | [106] |